Syntax Magazine

F

SYNTAX

Serving Timex-Sinclair
Personal Computers

A PUBLICATION OF THE HARVARD GROUP

VOL. 4 NO. 3

ISSN 0273-2696

MAR. ,1983

IN THIS ISSUE

8K Programs

Math . 8

Where To Move RAMT0P...9

Pledge Keeper..,. . 10

Direct Input Horizontal
and Vertical Line

Graphics . 14

Real-Time Soft Clock.. 15

Do Or Die . 18

A Sojourn at

CompuServe . 4

Get Your System

Together . 16

Book Review
Computers For Kids —
Sinclair ZX81 Edition. 14

Classified Ads . 21

Dear Editor . 12

Hardware Project

Reverse Video Monitor. 19
Hardware Review
E-Z Key 60 Keyboard. ... 6
Machine Code Programming
Routine Elimination. . . 21
News, New Products .... 1 , 2
Program Improvements....!
Software Reviews

Snake . 16

Reference Card . 20

Users' Groups . 3

Vendor Report . 3

TIMEX PRINTERS ON THEIR WAY

Timex printers are en route to distributors,
according to a Timex source, and should be in
retail stores in March. TS2040 printers
offer 32-column thermal printout and require

no interfacing. Price: $99.95.

KOPAK INTRODUCES NEW KEYBOARD

Kopak Creations' new keyboard, ^ready in 15

weeks, plugs into internal ZX/TS keyboard
connector. Full-size keyboard features on/
off switch, standard space bar and RETURN, 2
ENTER and 2 shift keys, shift lock and 4
single-stroke keys (comma, colon, $, DELETE).
Optional numeric keypad extra (price not
set). Preproduction orders $69.95 + $5.50 P&H.
Full price is $99.95+$5.50 P&H. Kopak Crea¬
tions, 119 Peter St., Union, NJ 201/864-4410.

DRIVE TO RUN CP/M IN THE WORKS

Kopak Creations and Aerco are working jointly
on a ZX/TS disk drive to run CP/M (world's
most common disk-based microcomputer operat¬
ing system.) Aerco says the drive will be
available in 3 months. Now work continues on
the software and getting a license from Digi¬
tal Research, CP/M's orginator. Aerco's
spokesperson would not predict the drive's
price. Aerco, Box 18093, Austin, TX 78760-
8093, 512/ 385-7405.

Index to Advertisers WANTED: ASSEMBLY LANGUAGE PROGRAMMERS

Brainchild Computer . 4 Proprietary International needs assembly

Byte-Back . 10 language programmers for their unreleased

Discount Software . 6 ZT21000 (Jan. 83). You'll get a production-

Frog Software . 18 model unit, documentation and a marketing

Intercomputer . 7 contract, but you'll pay $1000, says Steve

Kopak Creations, Inc... 17 Zwaska of PI. Send a short resume (with

Memotech Corp . 5 phone number) and sample program (plus check)

People's Computer . 20 by 3/21/83. Info: Randy Wear, 800/356-8392,

Softsync . 11 PI, 131 LaSalle Rd., Streamwood, IL 60103.

NEW PRODUCTS AND SERVICES

New ZX/TS software: Blackjack and
Hi-Lo (tape 1); Mastermind, Super¬
mind and Guess (tape 2); Escape,
Snake and The Trap (tape 4). Each
tape, $10.95. Compuwiz Software,
POB 390078, Mt. View, CA 94039.

Plug-in speech module, The Parrot,
makes 64 English-language sounds.
Combine sounds (allophones) to gen¬
erate words, phrases, sentences and
sound effects. Package includes:
software, directions, jack for 4-
or 8-Ohm speaker. Power socket
permits more power. R.I.S.T. Inc.,
$69.95, 921 Port Washington Blvd.,
Port Washington, NY 11050, 516/883-
8865. In Canada: Integrated Data
Systems, 11 Brighton Ave., Toronto.
Ontario, Canada M4M 1PW.

Guide to ZX Spectrum Resources . a
92-page illustrated book, details,
reviews British products for the
new Spectrum/TS2000. $6.50, Micro¬
scene, 6 Battenhall Road, Harborn,
Birmingham B17 9UD, UK.

SCREEN-CALC, ZX/TS electronic
spreadsheet program, holds 450
user-defined entries as either in¬
put data or calculated results.

You can define any entry in terms
of other entries. Built-in fea¬
tures total and average columns and
rows and can locate entries by
name. On cassette. Banta Soft¬
ware, 8088 Highwood Way, Orange-
vale, CA 95662, 916/722-4895. '

Hidden Words, ZX/TS word search
game, conceals words in the playing
grid. Word editor lets you change
words; four levels of play. On
tape, 16K required, $9.95. Soft¬
ware Unlimited, P.0. Box 147,
Grandview, MO 64030.

Construct current buffer for tape
recorder remote jacks. Excessive
current can damage the relays in
your ZX99. Schematic package al¬
lows you to construct buffer to

reduce remote jack current to 10
mA. ZX99 can't tolerate more than
130 mA. Schematic package and in¬
formation on constructing current
buffer for input/output recorder
jacks using simple parts. Z-WEST,
P.0. Box 2411, Vista, CA 92083.

KBD-1 keyboard for TS1000 has 58
plunger-type keys, 12 spare keys,
internal or external PC board in¬
stallation without solder, full
space bar, dual shift keys with
shift lock, electronic shift/ un¬
shift, repeat and fast repeat on
all keys, keyboard entry disable
and instruction manual. $84.95
plus $4.95 P&H. Half-size 5 1/4"
disk drive is in the works. SYNER¬
GISTIC, P.O. Box 411023, Chicago,

IL 60641, 312/772-7461.

Machine code debugger for BASIC
programs resides in the top 2.5K of
16K. STEP can single-step BASIC
lines and be set to RUN to condi¬
tional breakpoints or break after a
specified number of loops. $14.95
plus $2 P&H. HOT Z, machine code
monitor and disassembler, is now
available on four 2716 EPROMs ad¬
dressed to 8-16K memory block.

Chips require Hunter memory board
or home-made EPROM reader for ac¬
cess to HOT Z monitor. Four tested
2716s, $40. Sinware, Box 8032,
Santa Fe, NM 87504.

Problem Solver, an external voltage
regulator, eliminates loading and
overheating problems and includes
on/off switch. Schematic, parts
list, assembly directions, $12.95;
kit, $24.95; wired and tested
$49.95. Original Programs, 3763 W.
Crocus Dr., Phoenix, AZ 85023.

User-friendly 16K Ohm's Law pro¬
gram. On cassette, $15 plus $1
P&H. Keyboard conversion plans for
ZX80/ZX81 , TS1000 includes decoding
shift keys and reset, $5 plus $1
P&H. Arizona residents add 6% sales
tax. Spectra Computer Products,
P.O. Box 41795, Tucson, AZ 85717.

2

VENDOR REPORT

USERS' GROUPS

In this new department, you'll find
out about ZX/TS vendors — what prob¬
lems exist and which have been
resolved, who's in business and
who's not. If you're having prob¬
lems with a vendor, let us know.
We'll help find a solution. — Ed.

OUT OF BUSINESS: Synchronize, Box
1667, Kerrville, TX 78028, adver¬
tised in Winter 82 SQ. If you have
a problem with them, call SYNTAX.

ZXPress Compiler from Non-Trivial
Solutions is now available only
from Proprietary International.

They should fill all back orders
and inquiries before press time.

If you have a problem, contact
Randy Wear, Marketing Director,
800/356-8392. PI, 131 LaSalle Rd. ,
Streamwood, IL 60103.

We've heard complaints about Norris
Radio and Electronics' repair and
return practices. We telegrammed
Tracy Norris about these problems
(no phone listed) , but he has not
responded. Norris is a ZX/TS re¬
pair shop in Slidell, LA.

Neither have we heard from SMUG,
the Sinclair Midwest Users' Group
in Fort Wayne, IN. Some readers
wrote they did not receive software
they ordered from SMUG. Last month
we wrote to SMUG to inquire; we'll
let you know if they answer.

Gladstone Electronics is working on
catching up on their US shipments.
Readers have reported receiving
cancelled checks promptly, but no
merchandise up to two months later.
Howard Gladstone says US shipments
are now about 4 weeks behind, with
Canadian shipments on schedule.

They increased their staff and
shifts to remedy the problem. You
can now talk to Gladstone until 1
AM EST. Ask for head troubleshoot¬
er Pauline Sampson in Buffalo, NY,
at 716/874-5510.

Bakersfield, CA: Bakersfield
Timex/Sinclair Users' Group, Don
Stewart, 2617 Anza St., Bakers¬
field, CA 93305, 805/871-7024.

Detroit, MI: Sig-Sinclair c/o
SEMCO, Don Bicht, P.0. Box 02426,
Detroit, MI 48202, 313/535-6253.

Fredericton, NB, Canada:

Fredericton Sinclair/Timex Users'
Group, John Palmer, Fredericton,

NB, Canada, 506/454-0705.

Huntsville, AL: Sinclair Users'
Group, Bob Boyle, 7705 Martha
Drive, Huntsville, AL 35802,
205/883-4354.

Manitoba, Canada: The Manitoba
Telephone Systems Sinclair ZX81
Systems Users' Group, Ben Landry,
204/888-4516.

Modesto, CA: Time-Sync Group for
Central Valley California, Thomas
Eckle, 3716 Corte Madera St.,
Modesto, CA 95350.

Palatine, IL: The Sinclair Users'
Network (SUN) , nationwide users
group. Diana Wright, 2170 Oak
Brook Circle, Palatine, IL 60067,
312/934-9375.

Portland, OR: Portland Area Timex/
Sinclair Users' Group, Michael
Veine, P.0. Box 3153, Portland, OR
97208, 503/774-9637.

Redwood City, CA: ZX Micro Club,
c/o Ampex Corp., Don Femling, 401
Broadway M.S. 2-04, Redwood City,
CA, 415/367-3454.

PROGRAM IMPROVEMENTS/REFINEMENTS

To get a heart without a bite taken
out of it in Sweetheart (Feb. 83)
change line 120 to: FOR B=7 TO 24.
New Syntactic Sum is 22457.

John Sampson, College Point, NY

3

CHANGE YOUR

TIMEX/SINCLAIR 1000 DISPLAY
TO FULL COLOUR GRAPHICS

with

KOLORWORKS

LOOK AT THE FEATURES ! ! !

* Plugs into ZX81/1000 (edge connector)

* All text will run on the color tv

* Module contains it's own memory

* User defined characters & graphics up to

256x192 pixels

* Latest technology with TMS991 8 VDP

(32 sprite levels)

* Module contains extension of basic commands

including: PAPER/INK/BORDER/BIN/
SPRITE/OUT/INP / etc.

for $149.95

Use your KOLORWORKS immediately with a
game cassette for $9.95

This delightful game is designed for hours of fun using some
of the color graphic capabilities of KOLORWORKS. The
cassette also contains a short program to familiarize you
with some of the commands and graphics.

MAIL TO:

BRAINCHILD COMPUTER WORKS, INC.
P.O. Box 506
Pewaukee, Wl 53072

Price + Qty. _ Am ou nt

KO LOR WOR KS

$149.95

CASSETTE

9.95

Shipping and Handling

4.95

$4.95

Wi. Res. add Sales Tax

My n check EH money order enclosed

TOTAL

Name

Street _

City _ State _ Zip

Please allow six to eight weeks for processing. Thank you.

For further information - Send $2.00 (credited to order)
WATCH FOR:

"GAAMWORKS" -

Joystick Ports / Sound / Cartridge Slot

A SOJOURN AT COMPUSERVE

CompuServe Information Service
is available to ZX/TS owners with a
modem and the proper software.
(Modems allow two or more computers
to communicate via phone. SYNTAX
Jan. 83 describes one available
ZX/TS modem.) For $5/hr. (initial
$100 subscription fee), you get:
electronic mail, newspapers and
magazines, banking, games, SIGs
(Special Interests Groups) , and a
special programmers area. You can
also store programs, up to 64K, at
no extra charge!

To access the system, you need
a user number and password which
you get from computer stores or
CompuServe (800/848-8990? in Ohio
call 614/457-8650). They also ex¬
plain log-on procedures and how to
hook up to the system.

CompuServe uses prompts
throughout. Because the menu is
slow, I prefer GO statements. For
example, if I tire of playing Wum-
pus, and want to call the Work-at-
Home SIG, I enter GO HOM-146 at the
prompt. CompuServe's computer then
looks up the particular disk file
and lets me access it.

This system supports many var¬
ied SIGs. One or more SYStem Oper¬
ators run each SIG. SYSOPs manage
the SIG, moderate the SIG C.B. sim¬
ulator, keep SIG database files
neat and help newcomers.

SIGs cover the entire world of
computing in the Personal Computer
Service area. That is, except for
ZX/TS computers. But there's hope.
I talked, via computer, with SYSOPs
on Computer and Electronics maga¬
zine SIG. They welcome a ZX/TS SIG
in their group (GO CEM-450) and
have a database available for ZX/TS
computer users.

Patrick Spera, Tinker AFB, OK

For more information, contact
CompuServe Corporate Headquarters,
5000 Arlington Centre Blvd, Colum¬
bus, OH 43220.— Ed

4

THE POWER.

AND THE GLORY.

Sinclair

TIMEX has given the world a breakthrough in personal computing power at an
affordable price. Now, to the power of the TS-1000, you can add the glory of
MEMOTECH ... of “piggy-back” compatibility: increased memory, a user-oriented
keyboard, a printer interface, a full spectrum of printers, high resolution graphics
and a remarkable range of new applications.

In short, MEMOTECH offers you the high-quality peripherals that
turn an introduction to computing into a versatile,
full-powered computer system.

New from Memotech . . .
the TS-1000 keyboard. And
state-of-the-art printers.

Keyboard. The Memotech keyboard
is a standard (Typewriter) keyboard
with TS-1000 legends. The keyboard is
cable-connected to a buffered interface which is housed in a Memopak case, and
plugs directly into the back of the computer or other Memopaks.

Printers. Memotech offers you a wide range of high quality printers .
including the SEIKOSHA GP 1 00A. The Seikosha GP 1 00A uses a 5 x 7
dot matrix printing format with ASCII standard upper and lower case
character set. Printing speed is 30 characters/second with a maximum
width of 80 characters. The printer uses standard fanfold paper up to

Baseline s the most economical
way to add memory to your TS-1000. It
is fully compatible with Memopak 1 6K and 32K
RAMs to provide you with up to 32K or 48K of RAM respectively.
Memopak 1 6K RAM. The Memopak 1 6K RAM offers expansion capabilities through
its “piggy-back” connection and is fully compatible with Timex or Memotech 1 6Ks to
give a massive 32K of RAM.

Memopak 32K RAM. Offers your TS-1 000 a full 32K of directly addressable RAM. It
enables you to execute sophisticated programs and store large data bases. It is also
fully compatible with the Timex or Memotech 1 6K RAMs to give you a full 48K of RAM.
Memopak 64K RAM. Turns your TS-1000 into a powerful computer suitable for
business, recreational and educational use. No additional power supply is required.
It accepts such basic commands as 10 DIM A (9000).

New Memocalc . . . push-button spreadsheet analysis. Allows the generation of a
spreadsheet of up to 7000 numbers with up to 250 rows or 99 columns. Every
time the command to calculate is given, all the numbers in the table are instantly
re-evaluated.

Memopak HRG. The Memopak High Resolution Graphics, with up to 192 by 248
pixel resolution, enables display of high resolution “arcade game” style graphics
through its resident 2K EPROM, programmed with a full range of graphics subroutines.
Memopak Interfaces. The Memotech Centronics parallel or RS232 interface paks
enable your TS-1000 to use a wide range of compatible printers. The resident
software in the units gives the ASCII set of characters. Both Memopak printer
interfaces provide lower case character capabilities and up to 8 column printing. The
RS232 Interface is also compatible with modems and terminals.

Order at no risk! If you’re not completely satisfied,
■■BjiaiiHB return any Memotech product within ten days for a
full refund. And Memotech's six month warranty
means we’ll repair or replace any defective part free.

I1111'1"1 . To order, use the order coupon or call our

' toll-free number 800/662-0949.

Dealer inquiries welcome.

. - ,

Meul to: Memotech Corporation I
7550 West Yale Avenue
• ™ Denver, CO 80227 i

Printer interface
High Resolution Graphics |
Memopak RAM

Peripherals that fit like a glove . . .
for an integrated system look.

m&opm&m

‘All prices quoted in U.S. dollars. Prices and specifications subject to change without notice.
“Please add an additional $5.00 for printer shipping charges.

16K RAM Baseline

$ 49.95

1 6K RAM

59.95

32K RAM

109.95

64K RAM

179.95

Memocalc

49.95

Keyboard with Interface

99.95

High Resolution Graphics

124.95

Centronics Parallel Interface

104.95

RS232 Interface

139.95

Printer Cable

19.95

GP 1 00A Printer Package**

399.00

Shipping and Handling

4.95

$4.95

Tax (Colorado residents only)

TOTAL

$

$

□Check DMasterCard DVisa

m CORPORATION^**

7550 West Yale Avenue • Denver, Colorado 80227
(303) 986-1 51 6 TWX 91 0-320-291 7

Account No. _ _ _ Exp. _ |

Name _ _ _ _ |

I City _ State _ Zip _ |

I Phone - Code: STX-03 I

I _ I

HARDWARE REVIEW

Product: E-Z Key 60 Keyboard

From: E-Z Key

Suite 75A

711 Southern Artery,
Quincy, MA 02169
617/773-1187

Price: $84.95 plus $4 P&H

E-Z Key offers a 60-key key¬
board in a 10" x 4" x 1/2" black
case that matches your ZX/TS. Each
gray key is slightly concave, has a
definite stroke and an audible
click. Keys include the ZX/TS's
standard 40 plus a numeric keypad,
a second shift key, a 4 3/4" space
bar and eight single stroke (no
shifting) keys. The single stroke
keys are FUNCTION, EDIT, DELETE,
STOP, single quote, double quote,
colon and semi-colon. Keyboard
screening matches the ZX/TS leg¬
ends. Shift keys are red and match
the red screening of the graphics
and shifted characters. The func¬

tion key and function legends are
yellow. Keywords, numbers and let¬
ters are white.

To install E-Z Key keyboard you
must take apart your ZX/TS case,
but no wiring is necessary. Gently
remove your ZX/TS keyboard cables
and replace them with the copper
laminated cable that comes with the
keyboard package.

E-Z Key's keyboard cable snaps
easily in place and appears quite
durable. It was the first time I
had taken my ZX/TS apart and in¬
stallation took me five minutes.

My new keyboard worked perfectly as
soon as I turned my ZX81 on.

I really like the audible click
of the E-Z Key 60. I find the
single stroke DELETE, EDIT, FUNC¬
TION and large ENTER keys very
useful. I also use the numeric
keypad and single stroke quote and
semi-colon regularly. I found the
keyboard easy to read and my entry
time improved significantly. E-Z
Key 60 Keyboard gave me a stronger
psychological sense of "working
with the computer."

I encoutered two problems with
my keyboard. First, OR and STEP
legends were missing from the key¬
board screening. Second, the back
of the keyboard rocked slightly on
the cable plug — not enough clear¬
ance under the keyboard. A tele¬
phone call to E-Z Key revealed that
both problems were being fixed.

They volunteered to fix my keyboard
before I could ask. E-Z Key also
said they plan to make bolder leg¬
ends for punctuation marks and an
improved instruction sheet.

I am pleased with my E-Z Key 60
keyboard. It is well designed,
comfortable to use, is completely
consistent with the style of my
ZX/TS computer and improves entry.
It's an excellent addition to your
ZX/TS system that will help you to
take advantage of all your comput¬
er's capabilities. I highly recom¬
mend E-Z Key 60.

Robert Masters, Tewksbury, MA

wmmxm is our tg as? you.

losTHurrr

'<**»»*»*

IMT€RCOMPUT€R IMC.

HARDWARE AND SOFTWARE PACKAGES

MAKE THE MOST OF YOUR TIMEX SINCLAIR 1000

MEMOTECH PERIPHERALS

MEMORY EXPANSIONS

16K RAM # PL7002 $ 59.95

32K RAM # PL7003 $109.95

64K RAM # PL7004 $179.95

HIGH RESOLUTION GRAPHICS (16K RAM)

# PL7007 $144.95

PLUG-IN KEY BOARD # PL7011 $99.95
CENTRONICS PARALLEL INTERFACE # PL7005
$104.95

MEMOTECH RS232 INTERFACE # PL7006

$139.95

PRINTERS

1 SEIKOSHA GP-100A PRINTER The revolutionary low-
cost dot matrix impact printer— Uses up to 9.5” paper

# PL7008 $349.00

- SEIKOSHA GP-250X PRINTER The most intelligent
programmable graphic printer— Uses up to 9.5” paper

# PL7009 $449.00

> PRINTER-INTERFACE CABLE # PL7010 $19.95
» MEMOCALC Software on plug-in EPROM cartridge—
Spread sheet analysis— Up to 7000 numbers (when
used with 64K) # BS200C $59.95

EDUCATIONAL ADVENTURE
SERIES

EDUVENTURE I Answer the questions encountered
in each classroom until you make it outside for RECESS
and the surprise that awaits you there. (Grade level K-3)

# ED3001 $12.95

EDUVENTURE II Each new situation requires either
your ingenuity or knowledge (or both) to avoid being
sent to the principal’s office. (Grade level 4-6) i

# ED3002 $12.95

EDUVENTURE III Solve complex puzzles to outwit i

your teacher and achieve the highest scores. (Grade .

level 7-9) # ED3003 $12.95

EDUVENTURE IV An agile mind and quick reflexes !

will get you through this maze of mysterious situations- !

to your DIPLOMA. (Grade level 10-12) # ED3004

$12.95

All programs use 16K RAM.

NEW products coming soon: Software on ROM/EPROM
CARTRIDGES— SOFTBOXtm . A software library which
can contain several ROM/EPROM programs. Plug in your
computer and instantly call any program from your
SOFTBOX — A full line of software and peripherals
for the "colorful ZX SPECTRUM/TIMEX
SINCLAIR 2000.

For more information, Free Brochure, and
Special Package Discount, write or call:

1C INTERCOMPUTER INC.

P.O. Box 90, Prudential Center
Boston, MA 02199 Tel: (617) 437-1190
Telex: 951141 COFAR

QSAVE A Hardware-Software Combination—
Allows a baud rate of 4000 to be achieved com¬
pared with only 250 on the normal SINCLAIR
ZX81— Loads and saves a full 16K in only 29
seconds— Works with 16K and 64K. # PL7001
$37.95

Dealers and Distributors Inquiries Welcome

Mail to: Intercomputer, Inc., P.O. Box 90, Prudential Center,
Boston, MA 02199

Shipping and Handling

Printer

9.95

Shipping and Handling

Memotech Products and QSAVE

4.95

Mass. Residents Tax

5%

Total

□ Check □ Mastercard □ Visa

HOME MANAGEMENT

• BILL ORGANIZER Keeps track of bills, amounts due,
date due, finance charges, payments made, etc. Sum¬
marizes all data for tax purposes. # HM5001
$14.95

• CHECK BOOK Balances and maintains your
checkbook. Finds all checks written to one payee easily.
Add a printer and it will even write checks for you.

# HM5002 $14.95

• ADDRESS BOOK Store, update and retrieve names,
addresses, and phone numbers. With a printer attached,
it will print mailing labels, sorts entries alphabetically
by name, or by Zip Code. Only remember part of a
name? It will find records from incomplete informa¬
tion. Code the entries for special purposes, i.e.
Christmas Cards, Party Invitations, etc. # HM5003
$14.95

• OCCASION CALENDAR Keep track of birthdays, an¬
niversaries, meetings and special events. Have your
calendar appear on the screen at the touch of a key.

# HM5004 $14.95

All programs use I6K RAM.

ENTERTAINMENT

•MISSILE LAUNCHER Challenge the enemy by
destroying his ammunition stored in different locations.

# FG1002 $12.95

• KRAZY KONG A new version of the popular arcade
game. This program has all the features of the original
and is every bit as fast. # FG1013 $12.95

• GHOST HUNT Gobble your way through a maze of
Ghosts, Power Pills, etc., etc., very fast. # FG1014
$12.95

• MAZE DRAG RACE Drive through a giant maze 9
times the size of the screen, watch out for other cars,
rocks, oil and ice. A really superb machine code
game. # FG1015 $12.95

• DEMOLISHER Design an intelligent strategy to
demolish a growing wall before it crushes you.

# FG1005 $12.95

• MCODER Compiles a BASIC program into machine
code— Extremely simple to use— Write and debug your
Basic programs— Enter the MCODER— the Basic pro¬
gram will be compiled into machine code as you
watch. # PT4001 $18.95

• RETURN FROM SPACE # FG1001 $12.95
•JEOPARDY # FG1003 $12.95

•VEGAS # FG1004 $12.95
•AIR ATTACK # FG1006 $12.95

• GUARD THE PRESIDENT # FG1007 $12.95
•SUBMARINE #FG1011 $12.95

• COMBO PACK I Contains Return From Space and
Missile Launcher # FG1008 $18.95

• COMBO PACK II Contains Vegas and Jeopardy

# FG1009 $18.95

• COMBO PACK III Contains Demolisher and Air Attack

# FG1010 $18.95

• COMBO PACK IV Contains Guard The President and
Submarine # FG1012 $18.95

All programs use 16K RAM.

Limited warranty— Defective Software will be replaced if returned within
30 days— Memotech Products: 180 days— Seikosha Printer: 90 days

MATH— 8K/16K

Use Math to introduce your
children to the ZX/TS and give them
experience with basic skills of
addition, subtraction, multiplica¬
tion and division. Math provides 4
skill levels with 10 problems in a
set. Students get 3 tries on each
problem before getting an answer.

Use the mix-up choice to choose
randomly among the 4 operations.
Division is protected from remaind¬
ers, and subtraction never yields a
negative answer.

Enter the listing in FAST mode,
then switch your ZX/TS to SLOW and
SAVE by typing RUN 100. Math self¬
starts and contains input prompts.

Inverse graphics are:

650 six graphic shift D
1120 graphic shift space
1130 graphic shift H
1140 graphic shift space
1150 graphic shift H
1240 graphic shift H, A, H, A

between words graphic shift H
then repeat beginning sequence.

Barry Boyer, West York, PA

20 REM # MATH PRACTICE #

30 REM * BY B . L . BOYER *

SEM ***********************

50 REM

50 LET I=INT (D/E)

70 LET D=I*E
50 LET D $ =5TR$ D
30 RETURN
100 SHUE "MRTfflf"

10-* ^ "PLEftSE TELL

ME YOUR NAME
120 DIM G$(10)

130 INPUT G$

140 DIM B$(5,14)

150 LET B$ ( 1) /ADDITION**

150 LET BS 1 2) sr" SUBTRACTION"

JZ2 hEX (31 =" MULTIPLICATION"
150 LET B$(4) =“DIUISION**

190 LET B $ (5) ='*MIX -UP-

200 LET GUESS =0

210 LET R=0

220 LET U=0

230 RAND

24*0 CLS

250 PRINT "THANK YOU, **; GS; AT 1
j 1; *'NOU , PL ERSE SELECT**; RT 2,1;"
1- <+) BS ( 1) RT 3,1; "2. <-)

RT ^vi;M3. cx) **;b$C3);rt
?) *(51 ‘^B*<4);RT 6,1; "5. <

260'* IF INKEY* <>**** THEN GOTO 26©
122 XP^INKEEY*.— THEN GOTO 270
280 LET R* ss XNK EY*

290 REM * CHECK FOR URLXD ENTRY
300 IF CODE ft* <29 OR CODE ft* >33
THEN GOTO 2S0
310 LET SL=UAL R*

32© LET R=SL

330 PRINT RT 8,©; "YOU PICKED *’;
ft; ** *•; B$ (R)

34-0 PRINT RT 10,0; "NOW PICK DIE
FICULTY"; AT 11,0; "LEUEL 1 TO 4."
350 IF INKEY * < > " " THEN GOTO 35©
360 IF INKEY*-**** THEN GOTO 300
370 LET C * = INKEY $

380 IF CODE C* <29 OR CODE C*>32
THEN GOTO 380
390 LET C=URL C$

4*00 FOR K = 1 TO 10
4.10 FRST

4.20 IF SL =5 THEN LET RsINT (RND
*4.) +1
4.30 CLS

4*4.0 PRINT RT 1 , 1; B* (ft) ; TRB 17;*’
LEUEL "; C; RT 6 , 10; "PROBLEM "; K
450 DIM D* CO
460 DIM E*(C)

470 IF C>1 RND R>=3 THEN DIM ES
( C - 1 )

480 IF 02 RND ft =4 THEN DIM ESC
C— 2)

490 LET D*=STRS (INT (RND *9 999)
+0>

500 LET E*=5TR* CINT C RND #9999/

510 LET D-URL D$

52© LET E=URL ES

530 IF D >E THEN GOTO 600

54© LET T*=ES

550 LET TEMP=E

560 LET E=D

570 LET ES=DS

58© LET D=TEMP

590 LET D$ — T $

600 IF (INT (D/E) OD/E) RND R*4

THEN GOSUB 60

610 LET T=LEN STRS D

620 LET 5=LEN STR* E

630 SLOW

640 IF ft <4 THEN PRINT RT 10,10-
T; DS; TRB 10-5; ES; RT 12,5;" - ”

' 650 IF ft =4 THEN PRINT RT 14,5; "
mmhm"; RT 15, 5— S; ES; AT 15,5; " J **
; RT 15,6; D*

66© IF ft=l THEN PRINT RT 11,4; "

4“

67© IF ft =2 THEN PRINT RT 11,4; **

X"

68© IF ft =3 THEN PRINT RT 11,4;

690 PRINT RT 21, 0/ *

700 INPUT RNS

710 IF R=1 THEN LET CORftNS=D+E
720 IF ft=2 THEN LET CORftNS=D-E
730 IF ft =3 THEN LET CORRNS«D#E
740 IF R=4 THEN LET CORRNS=D^E
750 PRINT RT 20,0; "

RT 21,0; **

tt

760 IF CORRNS =RNS THEN GOSUB 9©

0

770 IF CORRNS < > RNS THEN GOTO 1©
4©

780 NEXT K
790 CLS

800 PRINT RT 1, I;B*( SL/; TRB 17;
"LEUEL ** ' C

810 PR INT RT 9 , 1 ; G S; RT 10,1; ‘*|8S
WSSS^y RT 12, 1; R; " RIGHT RND " ; W
; *" WRONG**

8

WHERE TO MOVE RAM TOP?

820 FOR 1=1 TO 30
330 NEXT X _

TSll 1R X|«iNjj RT — 1 11 “MHMi *■— M : &

f'iflT 21™ "ENTER CY) ES OR l
350 IF INKEY* < > " " THEN GOTO 35©
360 IF INKEY $=" " THEN GOTO 360
870 LET fi*=INKEY*

330 IF CODE ft $ =62 THEN GOTO 200
390 STOP

900 REM **RECOG. CORRECT ftNSUER

910 LET R=R+1

920 LET F*=STR$ CORftNS

930 LET U=LEN F$

94-0 LET GUESS =0

950 FOR J = 1 TO U _____

960 PRINT RT 18 , 20 ; "HHMEig&" ; ftT

970 IF ft 04 THEN PRINT ftT 13,18
-U; F$ CU-U+i)

930 IF ft =4 THEN PRINT ftT 13,6+T

~u; f$ cu-u+i>

990 PRINT RT 10, 20; "YOU RRE" ; RT
11,28; "CORRECT"

1008 NEXT U
1010 FOR 1=1 TO 15
1020 NEXT I
1830 RETURN

1040 REM * INFORM OF WRONG ftNSWER
1850 LET F $ =STR $ CQRftNS
1068 LET U=LEN F$

1070 IF GUESS =2 THEN GOTO 1260

1030 FOR U=1 TO U _

1890 PR INTRT1&, 20; ftT

11,20; "gnaagaaiag"

1108 FOR 1=1 TO
1118 NEXT I

1120 IF GUESS =0 RND ft<>4 THEN PR

TMT QT 1 ^ i uBm

1130 IF GUESS < > 0 RND ft 04 THEN P
PINT RT 13 . 10-0; "M"

1140 IF GUESS=0 RND R=4 THEN PR I
NT RT 13,6+T-U; "B"

1150 IF GUESS O0 RND ft =4 THEN PR
INT RT 13,6+T-U; "$g"

1160 PRINT RT 10,20; "YOU RRE" ; RT
11,20; '• WRONG "

117© NEXT J
1130 FOR 1=1 TO 5
1190 NEXT I

1200 LET GUESS =GUES5+1
1210 PRINT RT 10,2©;" ";RT

11.20; "

1220 PRINT RT 13,20,* "YOU HRUE"; ft
T 14,20; 3-GUESS; '* CHRNCES"

123© IF GUESS =2 THEN PRINT RT 14
, 28,* ";RT 17, 20; G$; RT 13,20; "TH
INK HfiRDER"

1240 PRINT RT 21,0; "=

1250 GOTO 700
1260 LET U=W + 1
1270 PRINT RT 13,20;"
T 14 , 20; " "

128© FOR J=1 TO U
1290 PRINT RT 10,20;"
” ; RT 11, 2© ; "| -

ft

1300 IF R O 4 THEN PRINT RT 13,1©
~J; F$ CU-U+1)

131© IF ft =4 THEN PRINT RT 13,6+T
-J; F$ (U-d+1)

1320 PRINT RT 10,20; "THE CORRECT
51 ; ftT 11 , 20; "RNSUER "

1330 NEXT J

134© FOR 1=1 TO I©

1350 NEXT I
1360 LET GUESS =0
1370 GOTO 78©

3YNTRCT IC SUM: 53397, 8K ROM

Many programs that put machine
code routines above RAMTOP tell you
to lower RAMTOP first. This pro¬
gram calculates just what decimal
numbers to POKE to put RAMTOP where
you want it.

Enter the program as listed.
Press RUN, then follow the prompts.

Richard Graffius, N. Versailles, PA

RAMTOP is a system variable that
tells you where the computer thinks
the top of memory is. You can
change it to protect machine code
(see SQ, Winter 82 p.20) or to
reduce the available RAM. To cal¬
culate where to move RAMTOP, first
figure out the standard RAMTOP for
your memory size. Add the number
of K of RAM you have to 16 (the ROM
uses 16K bytes — 8K of instructions
and an 8K duplicate) and multiply
by 1024 (bytes per K). Subtract
the number of bytes to reserve.
Enter the answer as the address
line 100 asks for. This program
also gives you the most and least
significant (MSB and LSB) bytes of
the address you enter. — Ed.

10© PRINT "ENTER RDDRESS OF RRM
TOP UftNTED"

110 INPUT MC
120 CLS
130 DIM H £45
140 PRINT

15© LET H (4) = INT CMC ,'40361
160 LET H C 3) =INT C CMC— H (41 *4096
3 .-256)

170 LET H (2) = INT CMC- C CH (43 *409
63 f (H(3) *256} ) /16)

130 LET H Cl) =MC- C CH C4) *4096) + CH
(3 3 *256) + CH (2) *16) )

190 PRINT MC; ** = LSB . . " ; H (23 *16+
H ( 13 ; ** " ; "MSB . . " ; H (4) *±6+*f C 33

20© PRINT
210 PRINT

22© PRINT "FOR ft NEW RftMTOP OF

** j MC

230 PR INT

S40^ PRINT "POKE 163SS , " ; H C2) #16

25© PRINT "POKE 16389 H (4) *16

+H (3)

260 PRINT
278 PRINT

280 PRINT "THEN TYPE ""NEW"" RN
D ""ENTER"""

29© PRINT RT 19,0; "TO FIND RNOT
HER, TYPE ""RUN”""

SYNTACTIC SUM: 32243, 8K ROM

9

PLEDGE KEEPER — 8K

Pledge Keeper simplifies
recording pledges and can be espe¬
cially helpful during telethons or
other fund raising events.

It uses ID numbers instead of
names, which are usually considered
privileged information. Your data
entry person doesn't need to know
contributor's names and addresses
but you can keep track of them for
your pledge committee to use.

Enter the listing and RUN.
Pledge Keeper asks for ID number,
pledge amount, and kind of pledge
(W for weekly, M for monthly, Q for
quarterly, S for semi-annual or Y
for yearly).

If you enter zero for a pledge,
the program displays the ID number,
and yearly amount of zero. Totals
or averages won't use the entry.

After your last entry, enter a
negative ID number and ENTER.

Pledge Keeper displays and totals
all pledges, the number of people

64K MEMORY
M-64 $119.9k^t

129.95 WIRED & TESTED
IN STOCK. SAME DAY SHIPMENT
All standard features included, plus lower 8K
of RAM can be disabled in 2K segments to
allow PROM or peripherals to be added.

EXPAND YOUR 16K SYSTEM

$59.95

If you have a Sinclair 16K RAM module and need
I more memory, expand it to 32K and beyond by usinq
[BYTE-BACK M-16 MEMORY MODULES.

You can’t connect two Sinclair 16K RAM modules together,

I but you can connect one Sinclair 16 K and one or more BYTE-
BACK 16K modules to get all the memory you need.

THOUSANDS IN USE WITH PROVEN RELIABILITY

M-16 $59 .®5 Kit. $69.95 wired and tested.

IN STOCK. SAME DAY SHIPMENT

BB-1 Control ModlllG. with 8 relays, 8 leds

& 8 inputs. $59 Kit. $69 wire and tested.
IN STOCK! SAME DAY SHIPMENT

95

MODEM with RS232 Port $1 1 9.Kit

$149.95wire
& tested.

90-Day Warranty On All Modules.
10-Day Return Priviledge
ORDER PHONE 803-532-5812

Add $4.95 shipping & handling to all orders.

BYTE-BACK CO. CHECKS

Rt. 3 Box 147 Brodie Rd.

LEESVILLE, SOUTH CAROLINA 29070 ■■■■L

who pledged, and gives the average
annual pledge.

Edit lines 10, 30 and 40 to
suit your particular needs or in¬
sert your organization's name.

Robert DeMunbrun, Rushville, IN

1 REM KEEPING TRACK OF PLEDGE
S

2 REM BY R « M « DEMUNBRUN

3 REM INPUT ID NO . .. PLEDGE j KIN
DCU FOR WEEKLY -M FOR MONTHLY -O F
OR ©URRTERLY-S FOR SEMI -ANNUAL -Y

FOR YEARLY »

4 REM TO "GET TQTRLS AND AUERA
GES INPUT NEGATIVE NUMBER FOR ID

1© PRINT TRB 10.1 "FIRST UNITED”

2© PRINT TRB 12; "CHURCH"

30 PRINT TRB 9; "PLEDGES FOR"

4-0 PRINT TRB 13; "1983“

4-2 PRINT

4-5 PRINT "ID"; TRB 5; "PLEDGE"; T
RB 14; "KIND"; TRB 20; "YEARLY"

50

LET N=©

60

LET T =0

70

INPUT I

8©

IF I<0 THEN

GOTO 840

90

INPUT P

100

IF P=0 THEN

GOTO 550

110

120

LET N =N + 1
INPUT

IF R$="W"

130

THEN

GOTO

600

140

IF A$="M"

THEN

GOTO

650

150

IF R$="0"

THEN

GOTO

700

160

IF R$="S"

THEN

GOTO

750

170

IF Rft="Y"

THEN

GOTO

800

550

PRINT I ; TRB

20;

P

560

GOTO 70

600

LET R=S2*P

81©

PRINT I; TRB

5; P

■; TRB

14; A$; T

A© 20; R
520 LET T=T4R

630 GOTO 70
©50 LET A-12*P
560 PRINT I; TRB
RB 20; R
670 LET T=T*R
600 GOTO 70
700 LET R=4*P
710 PRINT I; TRB
RB 20; R
720 LET T=T+R
730 GOTO 70
750 LET A=2*P
76© PRINT I; TRB
RB 20; R
770 LET T=T+A
780 GOTO 70
800 LET fi=i*P
810 PRINT I; TRB
RB 20; R

5; p; TRB

5; P; TRB

s; P; TRB

5; P; TRB

020 LET T=T+R
830 GOTO 70
8»10 PRINT

850 PRINT “NO. PLEDGES";

14-; R$; T

14; A$; T

14-; R$; T

14; A$; T

TRB 13;

860 PRINT "TOT PLEDGES"; TRB 12;
"$";TRB 13; T

870 LET U= (INT ( iT/NJ *100) ) /100
880 PRINT "RU PLEDGE"; TRB 12; " $
" ; TRB 13; U
830 STOP

SYNTACTIC SUM: 4394.. SK ROM

lO

TIMEX SINCLAIR 1000 SOFTWARE

SOFTSYMC, HMC.

METEORITES Shoot your
way out of the asteroid field.

16K $14.95

NIGHTGUNNER Maneuver

your tail gun as you fire at
enemy aircraft coming at you
from all directions. Features
on-screen scoring and bonus
points. 16K $14.95

GRAPHICS KIT 16K
GRAPHICS KIT 16K
GRAPHICS KIT 16K
GRAPHICS KIT 16K

GRAPHICS KIT Machine

code routines to help create
exciting graphics in programs.

16K $14.95

m

A

RED ALERT 16K

RED ALERT Scramble
between treacherous mountains
and fearsome aliens.

16K $14.95

SPACE RAID/

TS DESTROYER Two great

fast action 2K programs on one
tape. 2 K $14.95

HANGMAN Seven versions
of this classic guessing game
including a user creaTed library
of 500 words. 16K $14.95

ALIEN INVASION The best

TS/ZX version of this classic
game. 16K $14.95

2K GAMES PACK 6 great
graphics games on one cas¬
sette: COPTER PATROL, KILLER
WHALE, ASTROWALK, MONSTER
MASHER, STAR BLASTER,

DRAGON SLAYER. 2K $14.95

ALPHA/ VOWEL TUTORS

Two graphic tutorials designed
to teach the alphabet as well
as long and short vowels.

16K $14.95

MOTHERSHIP Zoom down

the Zarway corridor, dodging
and shooting drones, to get a
clear shot at the ominous
mothership. Amazing graphics!

16K $16.95

PROGRAMMERS
TOOLKIT 16K

PROGRAMMERS
TOOLKIT Machine code

routines to help programmers
write better software.

16K $14.95

MATH RAIDERS Teaches

children basic mathematics
through the use of a graphic
game. 16K $14.95

ADVANCED BUDGET

MANAGER Stores a year's
worth of projected and actual
income and expenses.

16K $16.95

THE STOCK MARKET
CALCULATOR two

programs to aid the investor in
calculating stock and option
investments. 16K $16.95

SPACE COMMANDO

This adventure takes you to
Zircon 12 to overcome the alien
forces and liberate the planet.

16K $14.95

SHARK’S TREASURE m

this adventure brave the deadly
shark infested waters to find the
treasure. 16K $14.95

THE ADVENTURES of
"QUEST FOR THE HOLY
GRAIL" and
"THE ELUSIVE MR. BIG"

Two different adventures on
one tape. Special feature
creates new versions every
time.

16K $17.95

SUPERCHESS The most

advanced chess available
featuring ten levels, tactical or
positional analysis, self play,
and will recommend moves.

16K $19.95

MAZOGS The most

elaborate, graphic maze
adventure available for the
TS/ZX computers.

16K $19.95

BIORHYTHMS Chart your
Physical, Emotional and Intel¬
lectual ups and downs.

16K $14.95

Write or call for free catalog
and program listing.

SOFTSYNC, INC., 14 E. 34TH ST., NEW YORK, N.Y. 10016 (212) 685-2080

DEALER INFORMATION AVAILABLE MCIVISA ACCEPTED

DEAR EDITOR

I bought and highly recommend
the two-tone Keyboard Audio Tone
from TV Services of Cambridge LTD,
Chesterton Mill, French's Road,
Cambridge CB43NP, UK. Keyboard
Audio Tone costs $18, is very well
made, compact and easy to install
(five solder connections).

I mounted an oversized heat
sink on the right of the standard
heat sink and it works fine. I
also added an on/off switch in the
black (ground) lead.

Keyboard Audio Tone tells you
when a key is hit, when your ZX/TS
accepts it and is ready for more
input — very handy on long text
lines in SLOW mode. It also sig¬
nals the beginning and end of SAVE
or LOAD, PAUSE and INPUT prompts.

Sidney Linton, Dunwoody, GA

For those readers who want to
add a full-sized keyboard, I recom¬
mend Double H. Electronics, 195
Lelan, San Antonio, TX 78242.

I bought a keyboard from them
two months ago. I installed it
with no knowledge of electronics or
its complexities. With the aid of
Mr. Hornung of Double H., I now
have a full keyboard with shift
lock, repeat, +, -, *, comma, ;, =,
DELETE and EDIT on separate keys.

Double H.'s keyboard (11" x 4")
is excellent in quality and has a
clean design. All my queries were
answered with dispatch, knowledge
and patience. Double H. provides
service that is uncommon today.

Complete assembled keyboard,
with plans for additional circuits
is $46. Parts for additional cir¬
cuits are $13.

William Mitchell, Ontario, Canada

I've been trying to program a
game that accepts input from two
players simultaneously. When I use
INKEY$ function and two keys are
depressed at the same time, the

CODE INKEY $=0. This creates a
problem. Is there any way I can
get around this using machine lan¬
guage? Maybe a hardware modifica¬
tion would help?

Randy Thompson, Eugene, OR

Write your own ML keyboard scanning
routine. Use ROM routines, modi¬
fying codes to suit your purposes.

Ian Logan's ROM Disassembly,
Part A, details the keyboard scan
routine at 02BB as well as other
keyhandlers. Briefly, eight half¬
rows of the keyboard, connected by
diodes to address lines A8-A15, see
a series of numbers with just 1 bit
high. Each key connects 1 address
line to 1 KBD line so the processor
can get a bit set by column and row
of the active key. Eight scans put
a number in the HL registers. The
monitor decodes characters in a ROM
table. No hardware needed. — KO

Is it possible to adapt pro¬
grams to save on tape so they can
be read and run on a Sinclair sys¬
tem in England (and vice versa)?

My brother in England has a
ZX81, and we'd like to communicate
through them. I understand the
problem is in transfer of data to
the graphic display because of
differences in the number of lines
on British television systems. Can
it can be overcome?

Wendy Roberts, Cambridge, MA

We bought many tapes in London and
they work fine. Unless you use MC
to manage the display file your¬
self, like Quicksilva's Defenders
game, you should encounter no prob¬
lems. If you use PRINT or PLOT to
put messages or designs on the
screen the differences in TVs are
irrelevant. — KO

I recently opened my TS1000 case
to install heat sink grease on the
voltage regulator to dissipate heat
more effectively. In the process.

12

I unwittingly damaged the keyboard
leads; however, I did manage to
salvage my computer.

Opening the case of your ZX/TS
can be hazardous to your computer.
You can damage the keyboard leads
with a kink or tear. So when you
open the case, first disconnect the
leads by gently pulling the flat
plastic cable out of its sockets at
the PC board front.

If the leads are damaged, you
can salvage them if the damage is
near the PC board and the conduct¬
ing strips are exposed on one side
of the plastic. Leads are actually
longer than required so carefully
cut them to just below the damaged
section and trim off the excess
plastic. Your TS1000 will work as
good as new after reinserting the
leads into the PC board connectors.

John Reinhardt, Madison, AL

As noted in SYNTAX'S Aug. 82
review of Memotech's 64K Memopak,
the pack causes screen interference
when mounted on the computer. The
trouble seems to come from a poor
ground-bond between the board and
its aluminum case.

To solve these problems, I
carefully drilled a small hole in
the side of the pack to the right
of the switch hole then mounted a
self-tap screw. I attached a short
lead to the screw and soldered it
to a ground point on the ZX/TS
board and brought it out the expan¬
sion hole corner nearest the screw.
This change cleared up most screen
interference.

Most remaining noise resulted
from a poor ground (0V) bond be¬
tween the modulator box and main
board. After resoldering, my dis¬
play is clean.

Jon Harder, Concord, MA

Much of the problem of poor RAM
pack contact with the edge connec¬
tor seems to result from pried
module contacts when you push the

pack on too tightly. Swab both
sides of the connector with TV con¬
tact cleaner/lubricant and slide
the pack on and off several times.
Then insert it all the way and back
it off about 1/8". (Partial inser¬
tion can cause wobble and other bad
contact problems. — KO)

Another cause of ZX80 only key¬
board lockups (Jan. 83 Dear Ed.) is
the keyboard membrane over a parti¬
cular key area may sag slightly
from continued use and heat. As
long as one key is not breaking
contact when released, none of the
other keys will work. Sometimes a
patch of heavy transparent tape
over the troublesome key area will
"bridge" the membrane enough to
lift it from the contact traces
beneath it.

However, if a key doesn't make
contact), carefully lift the key¬
board membrane and clean both mem¬
brane conducting area and contact
traces with a Q-tip moistened with
alcohol. This works if only one or
two keys are involved. If a half¬
row of keys stops functioning all
together, it's usually a sign of a
poor solder connection at a key¬
board diode or resistor, especially
on some of the earlier ZX80 boards.

Robert Hartung, Palmyra, NY

Can I create a user-defined
graphic symbol for the ZX/TS? I
have done a lot of ML programming
lately, but cannot find in the ROM
disassembly what part goes to the
graphics table for lookup and then
causes the 8-byte symbol to print
to the screen.

Clement Wehner, Scott AFB, IL

Yes, you can buy sprites by the ROM
(try Integrated Data Systems, 11
Brighton Ave., Toronto, Ontario, or
dk'tronics, 23 Sussex Rd., Great
Yarmouth, Norfolk, UK). Check our
big character programs (Jul.82 and
4K modification, Aug. 82) to see how
to read the ROM character set. — KO

13

BOOK REVIEW

Title:

Computers For Kids —
Sinclair ZX81 Edition

By:

Sally Greenwood Larsen

From:

Creative Computing Press

39 E. Hanover Ave.

Morris Plains, NJ 07950
800/631-8112, 201/540-0445

Price :

$4.95 (softcover, 64pp.)

Perhaps you justified buying
your computer by your children's
need for computer literacy in this
day and age. This book is a first
step toward a child's computer
literacy. It offers both incentive
and instruction during a child's
first few weeks with a ZX/TS. Af¬
ter reading this book with a ZX/TS
nearby, he or she is on the way to
being a pint-sized programmer.

Computers For Kids — Sinclair
ZX81 Edition is valuable as a
stand-alone course or a teacher's
guide. It proceeds slowly and
logically from "What is a Compu¬
ter?" to computer operation to
simple programming techniques.

I couldn't judge whether the
text was too ambitious or repeti¬
tive for children, so I asked my
eight-year old. He worked through
the book and reports it "taught me
a lot about computers and games and
what it can do for you and stuff."
(I think he found it entertaining,
informative and instructive.) He
also pointed out a couple concepts
I missed in the manual, showing
real understanding of BASIC funda¬
mentals. I was impressed by what
this book taught him.

But I feel Larsen spends too
much time on computer operation and
not enough on programming. She
could have more profitably used the
sections on operation to reinforce
newly acquired programming skills.

Still, if your under-14 chil¬
dren know nothing of BASIC and
microcomputers, this book is an
important investment.

John Connell, Middletown, RI

DIRECT INPUT HORIZONTAL AND
VERTICAL LINE GRAPHICS — 8K/1K

Horizontal and Vertical graph¬
ics lets you draw lines by direct
input and loops so you can draw
until you run out of memory.

Line 10, INPUT A$, selects the
type of line you want to draw-
horizontal or vertical.

For horizontal lines INPUT A
controls the Y-pixel coordinate,
INPUT B controls the beginning X
coordinate and INPUT C controls the
end X coordinate.

For vertical lines, INPUT A
controls X-pixel coordinate, INPUT
B controls the beginning of the
line, and INPUT C controls the end
of the line (Y-pixel coordinates).

After you enter the listing,
press RUN and "L" appears. Press H
or V to select the mode and ENTER.
The L cursor appears again — enter
coordinates A, B, and C one at a
time and your ZX/TS will draw the
line. To stop, hit STOP and ENTER
twice. Try this example which
draws a small rectangle (hit ENTER
after each mode and number):

1) Select H mode and press 9, 4 and
13. Select H mode again and hit
4 , 4, 13.

2) Press V for vertical mode and
hit 4, 4, and 9. Select V again
and hi t 13 , 4 , 9.

Lawrence K. Simmons, Riverside, CA

18 INPUT ft*

3© IF THEN GOTO S©

30 IP THEN GOTO 130

4.0 GOTO 1©

5© INPUT ft
8© INPUT B
7© INPUT C
8© LET Y*ft
9© FOR X=8 TO C
10© PLOT X / Y
11© NEXT X
12© GOTO 1©

13© INPUT ft
14© INPUT B
15© INPUT C
18© LJET Xasft
17© FOP YeB TO C
IS© PLOT X,.Y
19© NEXT Y
20© GOTO 1©

SYNTftCTIC SUM: 14097.. ©K ROM

14

REAL-TIME SOFT CLOCK

You can get a real-time clock
through hardware or software. The
hardware option, while usually more
reliable (especially with battery
backup), costs about $60 with
special purpose chips (M3M 5832).
Software clocks are cheaper.

Soft Clock creates a software
clock from the 3.25 MHz ZX/TS logic
clock using the system variable
FRAMES at decimal addresses 16436
and 16437. FRAMES tracks the num¬
ber of pictures sent to your TV
(60/second in the US). Soft Clock
keeps track of the value of FRAMES.

Soft Clock should be accurate
to a few seconds/day. It requires
just less than 2K RAM. You can use
it as a subroutine in application
programs. Just make sure you GOTO
200 at least every five minutes
(actually about 8.8). The severe
limitations are:

1. You can't turn off your compu¬
ter, even for a second.

2. You can't use FAST anywhere in
your program (FAST resets FRAMES to
65536) .

3. You can't use PAUSE.

Line Functions:

Line Purpose

7 F (fudge factor) corrects
for internal clock. Value
between 0 and 2 works best.

8 Initializes the count.

100 Looks at current FRAMES.

211 Checks that FRAMES isn't in

to the middle of a bit manipu-
215 lation. If it is, ignore

the count this time.

220 Resets starting count if

FRAMES rolls over from
32768 to 65556.

230 PINC is change in count.

250 SS is value of seconds.

Same for MM, HH.

340-74, 600 Pretty up output.

392 Print time at 4,20.

920 Lets you start clock at

any time you want.

960 Lets you set time.

P.J. Donnelly III, Centerport, NY

1 REM SOFTWARE CLOCK

6 CLEAR

7 LET f=1.605

8 LET OU =32768

9 GOTO 9©@

100 LET C=PEEK 164-36 4256 *PEEK 1
6437

105 RETURN
200 GOSUB 10©

210 LET NU=C

211 IF OU<NV THEN GOTO 215

212 GOTO 220

213 REM

215 IF OU>NU-256 THEN GOTO 200
220 IF OU < Kv THEM LET QU=OU+3£7
88

23© LET PINC=ABS C (OU-NU1 +FJ
24© LET GU=NU
250 LET SS =3S fPINC /60
260 LET M INC =0

27© IF SS > =60 THEN LET MINC-INT
(SS/60)

280 LET S5=5S-MINC*S0
290 LET MM =MM +MINC
300 LET HC =0

31© IF MM >=60 THEN LET HC=JNT i
MM 760)

320 LET MM=MM~HC*60
330 LET HH=HH+HC

340 IF HH >24 THEN LET HH=HH-24
370 IF HH < 10 THEN LET H$ = ,*0"

372 IF MM <10 THEN LET M*="0"

374 IF SS < 10 THEN LET Z$="0"

390 LET SS1=INT S3

391 PRINT AT 2,20;"

392 PRINT AT 4 , 20; H$+STR$ HH+" :
"*M$+STR$ MM+" : "+Z*+STR* SSI

410 GOSUB 600
499 GOTO 200
600 LET H* = ""

602 LET M* = ""

604 LET Z$ = ""

607 RETURN

900 PRINT' " SOFT CLOCK

901 LET P INC =0
905 PRINT

92© PRINT "SET TIME (S) OR STAR
T AT © (Z) "

930 INPUT 5*

935 CLS

940 IF'‘S$ = "Z" THEN GOTO 950
942 IF S*="S" THEN GOTO 960
944 GOTO 93©

950 LET SS=-4
952 LET MM=0
954 LET HH =©

956 PAUSE 0
958 GOTO 200

960 CLS

961 PRINT "ENTER TIME AS HH: MM!

SS”

962 LET P INC =0

963 INPUT T*

965 IF LEN T $ < > 8 THEN GOTO 953

966 LET MINC=0

967 LET HH=URL T* tl TO 27
96S LET MM=URL T*C4 TO 5)
969 LET SS=URL T* (7 TO 8)
971 PRINT "IS THIS RIGHT?

“ . Ir ; MM; " . " ; 55

973 INPUT S*

974 PAUSE 0

975 CLS

976 IF 5*0 "Y"
N GOTO 200

OR 5* < > "YES** THE

978 GOTO 961

SYNTACTIC SUM: 15979, 8K ROM

15

GET YOUR SYSTEM TOGETHER

Your ZX/TS is compact but can
give you that "all over the place"
feeling with snarled cables, loose
RAM pack problems, and instability.

One easy, but expensive, cure
is an encased keyboard that holds
your ZX board inside.

This cheaper way doesn't take
much time and uses materials you
may already have:

1) 10" x 16" shelving, 3/4" thick.

2) Double-stick transparent tape.

3) Four-inch foam mounting tape.

4) Adhesive-backed felt.

5) Rubber selfstick 1/2" squares.

6) Neon nightlight, 1/4 watt.

7) Extension cord (in-line switch) .

Raise your ZX/TS with four new
feet to make it more stable when
typing. This also raises your RAM
pack, reducing risk of crashes when
typing shifted characters.

Next, place your ZX/TS with
RAM, printer and power pack on the
board in a pleasing and simple
layout. Coil up the 9V DC cord and
leave just enough to reach your ZX
case. You can turn your ZX/TS on
and off with the AC cord switch.

Check your system layout for
convenience and find the shortest
wire length for each connection.

Use foam tape to mount the power
pack with its prongs to the back so
you can bring the extension to it
easily. Plug the night light into
the end and use a side connection
as the AC supply to the pack. When
the power is on, the light is on.

Pass the cables under your
computer to neaten up your system's
layout. Put double-stick tape on
each new rubber foot and position
your ZX/TS where you want it- — press
firmly until secure. Mount your
printer the same way.

One more plus: a 10" x 16"
board fits inside many attache
cases, so you can travel with your
whole system. A few bucks gives
your ZX/TS dignity.

Jon Harder, Concord, MA

SOFTWARE REVIEW

Program: Snake

Price: $9.95 plus $2.50 P&H

ROM/RAM required: 8K/16K
Printed listings? No
Program listable? Yes
Written in: BASIC and MC
Challenge: Great

Display: Good

From: ZETA Software, POB 3522

Greenville, SC 29608

You are a snake in this game
trying to maneuver inside a barn
and eat mice that randomly pop out
of holes. This would be easy if
you didn't have to worry about your
length increasing with every mouse
you eat. The game ends when you
touch the barn walls, cross your
own path, or eat 100 mice.

Snake comes well packaged on
tape with instructions and two sets
of stick-on labels for the direc¬
tion keys. Snake loads easily and
runs automatically.

Two user-selectable variables
give Snake thousands of game com¬
binations, although most are sense¬
less as the instructions warn.

These two variables are the snake's
speed and length of time the mice
freeze when they pop out of their
holes. The score, which increments
with every mouse you eat, is con¬
tinuously displayed at the bottom
of the screen.

My only complaint about Snake
is the top display line is slanted.
I think this is because the display
is generated by machine code. This
line does not affect game play and
adjusting horizontal hold control
on the TV helps. (Jon Bobst of
ZETA says the slanted line could be
due to a MC generated display, the
TV or hardware used — Ed.)

Snake provides many hours of
recreation and becomes a challenge
trying to beat your last score.

It's also compatible with all ZX/TS
8K ROM machines.

John Impellizzer i , Sterling Hts, MI

16

HOW

IT^M I/M I A a A ATI/MT KA

An ELECTRONIC FILING SYSTEM that can be used
for ANY type of data. Set up your own DATA-BASES
with this easy to use, menu-driven program with
AUTO-SEARCH facility. * 4ARfl

ORDER No. 03-1021 *l!r,u

BREAKOUT

Fast MACHINE CODE arcade-type game. If you
haven’t tried THIS version, you haven't played
“BREAKOUT” on the ZX81/TS1000. * * -oc

ORDER No. 03-4028 * l4a5

‘M’-Coder™

Creations Inc. — d/b/a Computer Discount Services

Draw and store complex images. Permits you to
create, mix, and save your own screen artwork. You
can mix graphics created with GRAFIX into another
program. By itself or on tape. This program is a
“must” for the CREATIVE PROGRAMMER.* 4 4nc
ORDER No. 03-6005 5 1495

Now you can write MACHINE CODE PROGRAMS on
your ZX81 with ‘M’-Coder. The first true MACHINE
CODE COMPILER for the ZX81 Computer. Simply
write your new program in BASIC, (or load an —
=EXISTING PROGRAM), press A-KEY and
‘M’-Coder will automatically compile it into
MACHINE CODE for you. ‘M’-Coder codes 99.9% of
all BASIC. Give all your programs that SUPER-FAST
professional look. Order ‘M’-Coder NOW to revolu¬
tionize your programming. Once you try ‘M’-Coder
you’ll never write basic programs againl Cjaqr
ORDER No. 03-5201 * 19

EXR DATE

MO

YEAR

Superb fast moving MACHINE-CODE fun. Have an
exciting time playing this EXCELLENT version of the
popular arcade game. * 4 iaR

ORDER No. 03-4027 * |430

VISA

CHARGE

□
□

INTERBANK NO

Sign

Ybur own PERSONAL OR SMALL BUSINESS ac¬
counting system. Contains refinements not usually
found in this type of program. “200 Transaction file”
can be SEARCHED, PRINTED or DISPLAYED. This
program has been throughly tested, and improved
through extensive use. * 4onc

ORDER No. 03-1022 $ 1995

NAME

ADDRESS

POWER
AT YOUR
FINGER TIPS!

ORDER No. 01-0007

KOPAICS “TOUCH-A-MATIC” gives you the power to
type more accurately and faster. It requires NO
WIRES, NO SOLDERING. It’s as easy as removing
the adhesive backing and pressing it into position.

Sub-lotol

Add sales tax

CITY _ STATE ZIP

up to $9.99 to $14.99 add$2.00
from $15.00 to $19.99 add $2.50
trom $20.00 to $24.99 add $2.85

from $25.00 to $29.99 add $3.45
from $30.00 to $39.99 add $3.70
from $40.00 to $49.99 add $3.95
over $50.00 add $4.25

$995

Pocking Sr Shipping
(See Chart)

Ibtal amount
enclosed or to
be charged to
my credit card

Enables you to play any tune through your T.V.
speaker, your cassette recorder or through an A.M.
radio. With ‘COMPOSER’ you can control the dura¬
tion of each note. And you can save your song on

ORDER No. 03-3012 $1995

ORDER FORM

TO AVOID DELAY PRINT CLEARLY
STOCK NUMBER AND DESCRIPTION

TOTAL

AUTOFILE

PUCKMAN

QSave

LOADS & SAVES 16 K file in 26 seconds instead of
7 minutes! Cleans up signal for a cleaner load.

• STRONGER, SHARPER DIGITAL SIGNAL

• CLEANER, FILTERED POWER • ENCODES YOUR
PROGRAM AND/OR DATE • Save time/Save i

• Baud rate increases from 250 to over <

must for all ZX81/TS1000 owners. TM * a fine
ORDER No. 04-1000 *09yo

DO OR DIE — 8K/16K

You are trapped in a Mayan
maze-like tomb. A block pixel in
the central chamber is the only
escape route. Use arrow keys 5,6,7
and 8 to move but watch for trap
doors that send you back to the
starting point. An hourglass timer
along the right side of screen
relentlessly spills away, starting
with the first move, so keep going.
Breaking walls or enlarging doors
disqualifies you.

Use a larger value in line 110
to increase your game time. Press
RUN to start and BREAK to exit.

Tom Shields, Franklin, NC

2 REM LINE 110 CONTROLS TIME
5 REM "S" SAUES "DO OR DIE"

10 REM L310 A320 SET "TRAPS"

15 FAST
20 GOTO 2000
50 SLOW
55 PAUSE 500

60 IF INKEY*="S" THEN SAUE "DO
OR DI@"

70 PAUSE 40000

Sinclair

Computing

Not just another newsletter, Sinclair Computing is a
typeset magazine with color illustrations, published
monthly. If you own a Sinclair or Timex/Sinclair
Computer you need Sinclair Computing. Every issue is
packed with informative Articles, New Products, Users
Groups, News Bits, Letters, Ask Sinclair Corp., Reviews,
Tutorials, Hardware Projects (many for under $10),
Programs, and Games.

FOR JUST $2.95 PER ISSUE

YOU CAN MAKE THE MOST OF YOUR
SINCLAIR or TIM EX/ SINCLAIR COMPUTER.

If after your first issue you are
not fully satisfied. ..cancel your
subscription for a FULL refund.

Sinrlair

Lomputing

□

□

I want one year for just $36.

I want two years for just $65.

Enclosed is my check or money order.

Sinrlair

Lomputing

NAME _

ADDRESS

BOX 95 SC

Glenmont. New York 1 2077

CITY _

STATE _ ZIP

105 LET T =0
110 LET L = 15
120 LET Z=©

125 LET X =2
130 LET Y —2

135 PLOT X . Y

136 PLOT X . Y
140 UNPLOT X,Y

150

7

IF

INKEY$="

5"

THEN

LET

1

X

II

X

180

IF

INKEY $="

6"

THEN

LET

y —v -

~ 17©

3.

IF

INKEY $="

7"

THEN

LET

Y=Y +

IB©

IF

INKEY $ = "

8"

THEN

LET

x=x +

' 190
310

Y = 12

LET

IF

OR

Z=Z + i

X =26 AND Y
X =26 AND

= 4 OR
Y =27

O

EX

li

XM

6 AND
=26 R

NO Y =35 THEN GOTO 12©

320 IF X =8 AND Y=22 OR X=12 AND
Y=22 OR X =44 AND Y=22 OR X=4S R
ND Y =22 THEN GOTO 12©

350 IF Z =L THEN PRINT AT T.. 31;"

355 IF Z=L THEN LET T=T + 1
36© IF Z=L THEN LET Z=0
370 IF T =22 THEN GOTO 5050
375 IF X =32 AND Y = 18 THEN GOTO

5100

500 GOTO 135
1175 LET A=A+4
1130 LET B =B -4
1135 LET C=C-4
1200 GOTO 2050
2000 LET R-0
2010 LET B = 56
2020 LET C =43
2050 FOR X=A TO B
2060 PLOT X..A
2070 NEXT X
2500 FOR Y=A TO C
2510 PLOT 8,Y
2520 NEXT Y

2700 FOR X=B TO A STEP -1
2710 PLOT X.. C
2720 NEXT X

2300 FOR Y=C TO A STEP -1
2310 PLOT A,Y
2020 NEXT Y

2325 IF A =16 THEN GOTO 3630

2350 GOTO 1175

3680 LET X =26

370© FOR Y =4 TO 16 STEP 4

3710 FOR 0=27 TO 39 STEP 4

3715 UNPLOT X,0

3720 UNPLOT X.,Y

3725 NEXT O

3730 NEXT Y

3805 LET Y =22

3810 FOR X =4 TO 52 STEP 4

3815 UNPLOT X,Y

3820 NEXT X

4000 FOR 1=0 TO 21

4-040 PRINT AT 1,31;

4045 NEXT T

4050 PRINT AT 10,10;" DO NOW"; AT
11, 10; " OR DIE"

4070 PLOT 32,18
4075 PLOT 2,2
5000 GOTO S©

5050 PRINT AT 10, 10; “YOU DIE"; AT

11,10;"

5©55 STOP

5100 IF T < 11 THEN GOTO 505©

5110 PRINT AT 10,10; "YOU WIN"; AT

11,10;"

SYNTACTIC SUM: 29469, 8K ROM

STX-3

18

REVERSE VIDEO MONITOR DRIVER

This circuit, using the concept
published in Electronics (6 Oct. 82
p.113) , drives a video monitor and
reverses video on demand. You can
get all parts except 74LS266 chips
at Radio Shack. Many parts stores
carry 74LS266s — we paid $0.60 each.

Caution: SYNTAX considers this

circuit developmental. It may need
adjustment or design change to work
with a specific computer and compo¬
nents. Use it as a place to start.

With one chip, one 2N3904 and
10 discrete components, the circuit
offers a simple, low-performance
solution. Just connect video, +5V
(30 mA drain) and 0V to your ZX/TS
to drive a Zenith ZVM-121 monitor.

Build this device on a small
experimenter board. Keep the wires
short and use coaxial cable for the
video connections. Lay the 2N3904
flat against the board, insulate
the circuit, and fit it under the
ZX/TS PC board. Or make 5V from

the monitor's 12.7V supply and put
the circuit inside that case.

Standard video signals switch
between 3 signal levels: white and
black (video) and sync (blacker-
than-black). Usually, picture sig¬
nals rest at black, drop regularly
to sync level, and rise to white.
ZX/TS video rests at white, drops
regularly to sync and dips to black
to create character dots.

We must separate the sync from
the video pulses, standardize the
video to switch between black and
white levels, and make sync pulses
flip from video to sync levels.

We use LS exclusive NOR (A OR B
AND NOT BOTH) gates. LS chips take
voltages above 2 volts as logic
highs and voltages below 0.7 volts
as lows. If both inputs are +5V or
both are 0V, output is high (+5V).
Leaving an input open or tying it
to +5 gives equal logical results.

So when the ZX/TS signal drops
from white to black, the gate does
not respond, while white to sync

+5V

IC1 74LS266

19

transitions change the gate output
state. In our circuit, pin 5 takes
composite video input and compares
it to 0V on pin 6. Pin 4 responds
by being at +5 for sync inputs and
0V for video. We obtain combined
horizontal and vertical sync at pin
4, but with levels reversed? we
correct these with the 2N3904.

Pin 9 also gets the combined
signal, but compares it to a lower
voltage signal that stays <0.7V at
ZX/TS black level, but goes high at
the white level. Both inputs are
low at ZX/TS sync level. These in¬
puts differ only during the black
level, so pin 10 follows video.

Pin 13 gets a reference signal
of +5 or 0V to choose the voltage
at pin 12 which will cause a high
voltage at pin 11 (video output).

Output resistors and diodes
create a new composite video sig¬
nal. When pin 4 goes to +5V, the
2N3904 brings the output to zero —
the sync level. When pin 4 is at
0V , pin 11 controls the output
between black and white levels. — KO

THE PEOPLE'S

COMPUTER
SUPPLY

MAKE YOUR TIMEX/SINCLAIR ZX80/81 DO EVERYTHING
FROM PLAYING GAMES TO SERIOUS BUSINESS
APPLICATIONS WITH HARDWARE & SOFTWARE FROM
THE PEOPLE'S COMPUTER SUPPLY.

MEMOTECH PRODUCTS OUR PRICE

01 64 K MEMOPAK . $169.95

0 2 32K MEMOPAK . 101.95

0 3 16K MEMOPAK . 54.95

0 4 NEW 16K BASELINE

MEMOPAK . 45.95

0 5 HIGH RES GRAPHICS .... 134.95
0 6 PARALLEL PRINTER

INTERFACE . 94.95

#7 RS232 INTERFACE FOR

PRINTER & MODEM . 139.95

0 8 PRINTER CABLE SPECIFY

RS2320R CPI . 19.95

ft 9 NEW DIRECT CONNECT

FULLSIZE KEYBOARD . 99.95

No soldering, plugs into edge connector
010 SE I KOSH A GP100A DOT
MATRIX PRINTER. . 325.00. . 425.95*
SE I KOSH A GP250X DOT
MATRIX PRINTER. . 369.95. . 469.95*

‘Parallel Printer Package Includes Cable & CPI In
terface

VISA, MASTER CARD & AMEX
& MONEY ORDERS

PERSONAL CHECK
ALLOW 2 WEEKS

OTHER PRODUCTS

01 ZONX 81 SOUND

GENERATOR . $49.95

02 HIGH QUALITY 9" GREEN

PHOSPHOR MONITOR . $115.95

Requires Direct Video Mod to ZX81
FREE Plans with order, simple in
stallation

03 WILLIAM STUART SYSTEMS
LTD

SPEECH SYNTHESIS

UNLIMITED

VOCABULARY FOR ZX80-81
TIMEX . 99.95

04 BIG EARS SPEECH RECOGN l~

TION SYSTEM . 99.95

CRASH GUARD PROTECTION FROM
ACCIDENTAL CRASHES . 19.95

Foreign Orders Please Add $5.50
U.S. Orders Please Add $3.00
Printer & Monitor Orders add $7.50

THE PEOPLE S COMPUTER SUPPLY
P.O. Box 664, Sidney, Nebraska 69162
Order Phone: Tel. 308-254-3208

SOFTWARE

REVIEW

Product:

Reference Card for the
ZX30 , ZX81 and Timex
Sinclair 1000

From:

Nanos Systems Corp.
P.O. Box 24344

Speedway, IN 46224

Price :

$5.95

"This card has it all!" ex¬
claims Nanos System's advertising.
And indeed it does. Reference Card
for ZX80, ZX81 and TS1000 comes in
a handy 3 3/4" x 8 1/2", 20 panel,
accordian-f old format. The card is
packed with information such as
brief descriptions of the BASIC
statements, commands, operators,
and functions.

Among its many tables and
charts Reference Card also has:
screen layout, character codes in
decimal and hexadecimal, error
codes, memory maps for the ZX80,
ZX81 and TS1000, and selected ZX81
ROM calls. Reference Card even has
tips on how to use FOR. ..NEXT and
IF. ..THEN statements.

These features alone make it
worth the price. But if you're an
assembly language programmer (or
want to become one) you need this
card. One side is a virtual
cornucopia of assembly language
information. It summarizes in¬
structions for: math, storing
registers in memory, loading
registers, moving memory to memory,
exchanging, shifting, comparing,
branching, data alteration, and
I/O. . Tables of flags, conditions,
and instructions which set flags
and a handy hexadecimal/decimal
conversion chart are also included.

This is a reference card, not a
tutorial, so don't expect it to
provide step-by-step instruction.

If you are fairly proficient with
your ZX/TS, this card will save you
the time and energy it takes to
thumb through manuals — you won't
want to be without it.

20

James Conrad, Seattle, WA

ROUTINE ELIMINATION — 8K/1K

Machine Language programs often
use BASIC routines to load REM
lines with ML code. If you PEEK
the code from the REM line and POKE
into protected memory for running,
you can eliminate the loading rou¬
tine by writing the REM line in hex
equivalents to ML decimal codes.

You have to initialize REM
lines to use in the loading routine
anyway, so why not just write it in
hex and skip the routine and all
its decimal inputs? Published rou¬
tines usually list the hex with the
ML program, but if not, you can get
it in the Appendix of the ZX81 or
TS1000 manual.

This example uses the 8K Syn¬
tactic Sum decimal listing (Jun.83)
converted to hex.

Before typing or loading the
program, regardless of memory,

POKE 16388, 225

POKE 16389, PEEK 16389-1 and NEW
to reserve memory space for the ML
routine. The 225 in the POKE is
derived by subtracting 1/2 the num¬
ber of characters (31) from 256.

Now enter the listing as shown.
Type SAVE, RUN and write down the
displayed value. Then PRINT USR
the value to get Syntactic Sum.

(In line 4, 16574 comes from adding
the number of characters in the REM
line (62) less 2 to 16514.)

Line 2 gets the first address
of reserved memory, which will be
the starting address of the ML rou¬
tine. Line 5 PEEKS hex from the
REM line, converts it to decimal,
and POKES it to reserved memory.

Rolf Miller, Ventura, CA

1 REM 217D40ED5B0C4-0DD2 100007
eBfl20087DBB2004DDE5GiC34E0600BB0
3231 SEC

2 LET R=PEEK 16388 +PEEK 18383
*256

5 PR INT ft

4 FOR X =165 14 TO 16574 STEP £

5 POKE ft, CREEK X-2S) *16+PEEK
(X + l) -28

6 LET ft-ft + 1

7 NEXT X

SYNTRCTIC SUM: 11175, 8K ROM

CLASSIFIED ADS: Reach almost
10,000 ZX/TS users for $9/line.

Send ad copy, 35 char. /line with
check to arrive by 15th of any
month. Include your tel. #, wheth¬
er or not it appears in ad. SYNTAX
RD 2, Box 457, Harvard, MA 01451.

***** KAMIKAZE *****f or ZX81/TS1000

* +16K; NEW sensational game of *

* SKILL from DC SOFTWARE... ONLY *

* $6.95 incl cassette, supply ltd *

* Box 928 Richmond VA 23298 *******

//2K Programs from 2-BIT SOFTWARE/ /
//"Making Treks" $9.95. Free //
//catalog games/educational soft-//
//ware. 2-BIT SOFTWARE, Dept SY2 ,/ /
//PO Box 2036, Del Mar, CA 92014//

' ' ' ' ' ZX SUMMER CAMP
Give Kids The SINCLAIR Advantage 1
to 6 wks. All levels, ages 9 to 18
Details $1, SASE (ref undable) , NEW
WORLD CONCEPTS, Bx 587 , Ogden, UT844 02

i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i i

MARBLES. MAZES AND SINK HOLES
A simple, non-destructive game of
skill and logic for all members of
the family. 15 levels of play, from
very easy to extremely difficult,
each with 4 different screen types
giving 60 full-screen displays.
Score displayed as time taken; auto
clock enforces time limit; auto run
and return to basic features. 100%
machine code program for ZX81 or
TS1000 with 16k RAM. Cassette $15.
CHARLES DRURY, 40 WESTGATE RD #5.
CHESTNUT HILL , MA 02167 '

- look FOR -

- INTEGRATED DATA SYSTEMS -

End Gliches/Loading Problems. SASE:
Programs , 3763 W Crocus ,Phx,AZ 85023

Turn Sinclair's ROM or your machine
code into assembler mnemonics with
"DAI". Tape/instr $9. Martin Irons
46 Magic Circle Dr, Goshen, NY 10924

FREE 1 2 programs on tape. SASE to:
Programs ,3763 W Crocus ,Phx,AZ 85023

21

** 15 ELECTRONIC DESIGN PROGRAMS **

* ZX81/TS1000 IK cassette $9.99 ***

* BRICK SOFTWARE PO Box 1455-X ****

* Bricktown, New Jersey 08723 *****

*** 60 Programs for ZX81/TS1000 ***
Each month get 10 programs on tape.
Games , Home , Bussiness , Utility f Educ.

6 months $19.99f 12 months $34.99
=========== BRICK SOFTWARE==========

PO BOX 1455-X BRICKTOWN, N.J. 08723

- OK you Hosers! The computer

drinking game has arrived! Can you
become the new "BEERMASTER" ? 1 Eh?

— ORCAVISION: #408, 10139-117 St.
Edmonton, Alberta, Can. T5K 2L3
For TS1000/ZX-81 (16K) $14.99 US.

GUESS MY NUMBER-2 players vs comput
er. Uses names and keeps score.
Listing — $0. 60/stamps. M. WILLIAMS,
BOX 1445T, EAST ST LOUIS, IL 62201

ZX81/TIMEX 1000. ..FINGERS SLIPPING?
Improve accuracy, speed input, feel
you keyboard with a "ClearTouch"
overlay. No modification reqd. Easy
to install. $9.95 + $1.50 SHP, CHK/MO
Visa/MC give exp. date. CT, Dept 40
PO Box 1136, Anacortes, Wa. 98221

ZX81/TIMEX-1K GAMES-5/$1.95-8/$2.50
"Sector Attack" ,"Star fighter", more.
KEN DOGGETT, 3436-H Fairway Oaks Dr
Lawrenceville , GA 30245

**** TECHNICAL APPLICATIONS ****
Software for electronic CAD and
formulas. All in BASIC, on tape,
with comprehensive instructions.
Send SASE for a list of programs
and prices to: Softec, P.0. Box
432, Fairport, New York 14450

SINCLAIR/TIMEX INTERFACING TO
ANALOG and DIGITAL Devices. J.V.
Kane And Co. 109 Ardmore Avenue,
ARDMORE Pa 19003. 215-649-1782

******T IMEBLASTER s******
A 1.7K M/L ARCADE GAME FOR SERIOUS
Players. For ZX81/TS1000 (16K RAM)
Send $12.95 To: CALLIOPE SOFTWARE
4130 COE DR NE, ALBUQ. , NM 87110

*** THE DEFINITIVE TAX PROGRAM ***
Fr 16K ZX81/TS1000. EASY DATA ENTRY
AUTOMATIC TAX COMPUTATION FOR EACH
CHANGE, INCLUDING INCOME AVERAGING.
Inf o:SASE , Cassette:10.95. ** LOP
2365 Newcastle, Cardiff ,Ca, 92007 **

- ZX/TS 16k NEWCOMER SET

I MT-SOFT ! Cassette & Listings
! TEACHER ! AMORTIZATION . . $6.95

i - 1 print-BIG . . . $7.95

MT-SOFT, Bx 2638, Aurora II. 60507

YOU CAN UNLOCK REAL COMPUTING POWER
wtih new KEY — now expanded to give:
UNLOCK-SAVE any ZX/TS cassette prog
PROTECT-move a program above ramtop
MERGE-join ramtop & workspace progs
BYTE-show # of ram bytes remaining.
Short ML tape with USR calls $10PPD
in US/Can. G. Russell - Electronics
RD 1 Box 539, Centre Hall, PA 16828

MULTI-FUNCTION WINKY BOARD II**New
SAVE filter cuts rampac "noise" for
clean easy loading tapes. DUPLICATES
any ZX/TScassette. SAVE on 2 cas¬
settes at once. Solves LOAD problems
AND MORE! Tiny lxl 1/2" openboard
interface needs no power no mods
$24PPD $18Kit G.Russell-Electronics
RD 1 Box 539, Centre Hall PA 16828

***** ZX81 - TS/1000 SOFTWARE *****
ENTERTAINMENT - EDUCATION
GAMES - TEXT ADVENTURES - BOOKS
Send For Catalog & FREE Game
Software Unlimited
PO Box 147 Grandview MO 64030

ZX81 Program: "RECIPE RETRIEVAL"
Store 200 recipes; sort, search, &
LPRINT routines - $19.95 ppd. USA
ck/mo CARRIAGE SYSTEMS, BOX 2066
TOLUCA LAKE, CALIF 91602 - 16K +

Drive a video monitor with your ZX-
81. Our DVC-1 direct video kit is
only $9.95. With the DVC-2 you can
switch select normal or REVERSED
video. Kit $20.45, fully assembled
$31.45. Get super sharp character
definition with our 12" B&W video
monitor, only $98.45. Random Access
Box 41770S, Phoenix AZ 85080

22

COMPUSETTE is a C-10 cassette which
is especially designed for micro¬
computer application by TAPEMASTERS
25 for $20.00 100 for $70.00

COMPUSETTE + is a C-20 cassette
25 for $22.00 100 for $77.00

VISA MASTERCARD C.O.D.

TX 214-349-0081 **OTHER 800-527-1227
10% Discount for Check with Order
P. 0. Box 38651*Dallas , Texas 75238
FREIGHT PREPAID*DEFECTIVES REPLACED

OUR POLICY ON CONTRIBUTED MATERIAL

SYNTAX invites you to express opinions related to any Sinclair computer or
peripheral, or the newsletter. We will print, as space allows, letters discussing items
of general interest. Of course, we reserve the right to edit letters to a suitable length
and to refuse publication of any material.

We welcome program listings for all levels of expertise and written in either
Sinclair BASIC or Z80 machine code. Programs can be for any fun or useful
purpose. We will test run each one before publishing it, but we will not debug
programs; please send only workable listings. Programs submitted on cassette can be
tested more quickly and with less chance of error.

In return for your listing, we will pay you a token fee of $2.00 per program we
use. This payment gives us the nonexclusive right to use that program in any form,
world-wide. This means you can still use it, sell it, or give it away, and so can we.

We will consider submissions of news and hardware or software reviews. Please
keep articles short (350-400 words). Again, we reserve the right to edit accepted
articles to a suitable length. We will pay 7 cents per 6 characters, including spaces
and punctuation, for accepted articles.

When you send in programs for possible publication in SYNTAX, please
include the following information:

• How to operate the program, including what to input if it does not contain
prompts.

• Whether you can run the program over again and how.

• How to exit the program.

• The Syntactic Sum (program published in Feb. 81 and Jun. 81; send SASE
for a free copy).

• What RAM size program requires.

• What ROM program uses.

We pay for this explanatory text at the same rate as for articles in addition to
payment for the program itself.

If you want us to return your original program listing or article, please include
a self-addressed, stamped envelope. Otherwise, we cannot return submitted material.

**FREE GAME PROGRAM! ISend Stamped**
*Envelope To:ZAMIS ENGINEERING, 251*
**First St . , Per rysburg ,0hio 43551**

SINCLAIR & MICROACE (8/16K) Utility
5K bytes of subroutines:

Base conversions-Binary-Decimal-Hex

Plot Circles & ASCII Code

Arctan-Radians-Degrees

Read addresses in Dec.& Hex

Memory remaining- 404-445-6544

M-WARE-Rt . l-Hiram,Ga. 30141

VISA & MASTERCARD-ppd.U.S.A. $11. 95

LEARN DATA HANDLING TECHNIQUES with
ZX Data Finder, a versatile file
manager for 16K ZX81s. All routines
thoroughly explained. Concepts and
dozens of memory saving methods are
analyzed. List/text $9.95-free info
Tom Woods Box 64 Jefferson, NH 03583

********** DOUBLE-UP *********
Merge 2,3 Or More Programs In Secs.
Listing $1, Tape $5. G.D. Forsythe
RD #1 Box 277A Landenberg PA. 19350

"PERSONAL FINANCES-PART I" for 8
Compound Interest Calculations &
"PERSONAL FINANCES-PART II" for 8
IRA & Simple Interest. LISTINGS
$7.95 ea TAPES $12.95 ea S&H $2.
SEE, BOX 787, Fallbrook, CA 92028

SYNTAX is published

monthly by a wholly-owned
subsidiary of The Harvard Group.

Syntax ZX80, Inc.

RD 2, Box 457, Harvard, MA 01451.

Telephone 617/456-3661.

12 issues, $29. Single issue, $4.

Publisher: Kirtland H. Olson
Editor: Ann L. Zevnik
Assistant Editor: Pamela Petrakos-
Wilson

Editorial Assistant: Pamela K. Vinal

© Syntax ZX80, Inc., 1983. All rights
reserved. Photocopying prohibited.
ISSN 0273-2696

YES! Please send me 12 issues of SYNTAX for $29. 3/83

□ My check for $29 is enclosed. □ Please charge my □ MasterCard
Make checks payable to: □ Diner’s Club □ American Express

SYNTAX ZX80, INC. □ VISA □ Carte Blanche account

account number _ _ _ _ _

exp. date _ bank number (MC only) _ _

signature _ _ _ _ _

Name _ Title - - -

Organization - - -

Address _ _ _ _

City _ _ _ State _ Zip -

Day Phone_( _ ) _ Evening Phone_i _ ) _

I own a □ Sinclair ZX80 □ Sinclair ZX81 Telephone orders call

□ TS1000 617-456-3661

23

SYNTAX

INTEGRATED DATA SYSTEMS
11 Brighton Av Toronto Ont M4M 1P3
Your 1 stop for AUDIOGRAPH, Bi-Pack
BYTE-BACK, DEAN, DATA-ASSETTE, EZRA
GRP, GRAPHICOMP, INTERCOMPUTER, IPS,
KAYDE, MEMOTECH, OASIS, RIST,ORBYTE
SINLCAIR, SIMULSION, SOFTSYNC, TIME¬
WORKS, ZODEX,eg4K Graphics ROM$76.10
Graphics Space Invaders $14. 90, FULL
AUTO REPEAT module $34.50,16K PANDA
RAM $63.60 (can+16K inside it) Star
Battle $24. 20, Home Inventory $18.70
Money Manager $24.20,ZXChess2$29.80
RIST PARROT voice synthesizer $129,
Min ord $25 W/MO+$1.50 P&H. Outside
CDN less 2 0 % (30% Home, Star , Money) &
Send that amt as US$. Ont res+7%PST
Deliv 5wk ARO. FREE 300 item list.

***********RC0 technical***********

Z-WRYTER-Word processor. Write, edit,
save text using powerful editing
functions. Supports ZXpr inter .Great
for notes, reports. $9.95

DISTACALC-Calculates great circle
distance and azimuth between any 2
points on earth using lat/longitude
File area holds 200 cities. Great
for hams-remar kably accurate. $11.95
Tape&manual-16K req.Add $1 postage.
RCO PO BOX 773D ST ANN MO 63074

35X26 ELECTRONIC WORKSHEET 16K $10!
SASE brings MFREEM Program & Cat.
EZRAEZRA, Box 5222 , SanDiego CA 92105

TOPNOTCH! Keeps running charts on up
to 20 stocks (16K) TAPE, INFO-$5. 50 to
EDBSOFT,Box 22,Keuka Park, NY 14478

***********************************
WIN A MINDWARE MW100 ZX/TS PRINTER
Send SASE To:MMl Comp. ,YAGSEE,

PO Box 155 , Vicksburg , MI ,49097 .

'k'k-k'k-klc'k'k'k'k'k'kic'kic'k'kic'klc'k-k'k'k-k'k'k'k'kic'k'k'kic'k

HAM RADIO LOGGING PROGRAM — ZX-LOG
Clock-calendar automatically logs
time & date. Search by any combi¬
nation of items. Ex: Find all Utah
QSO's who owe you a QSL. Additional
records can be used for notes. 16K
will hold 90 records, 48K-850. SASE
for info. $35 postpaid. Send call.
PSION ZX-CHESS (16K) mod. Save and
restart in mid-game. Print Screen.
Instr. $2 + SASE. Dennis Hevener,
1721 1/2 Holly Dr., Glendale, CA
91206. Telephone (213) 246-3265.

PAKGUY-Our version has power capsls
full screen maze,ghosts&FAST ACTION
ML ASTROIDS-8 directions;every rock
splits 3 ways. Cass. w/both 16K games
&ML-S7.FREE CAT. MILL RESEARCH 32749
Avalon Cr . Abbotsford, B. C. Can. V2T3W9

**CASH JOURNAL GENERAL LEDGER for

small business - $9.00

**REMEMBER & DOTTODOT games - $4.00

To : DGC POB1642 Roswell, GA 30076

HARVARD

GROLP

Bolton Road, Harvard, Mass. 01451

First Class

U.S. Postage
PAID

Harvard, MA
Permit No. 8
01451